1. Field of the Invention
The present invention relates to an endoscopic treatment tool that is used by being inserted into body cavities in a transendoscopic manner and being supplied with high-frequency current.
2. Description of Related Art
In the past, for the purpose of incision of polyps or the like, there have been known endoscopic treatment tools in which high-frequency current is supplied to a grasping portion having bifurcated distal ends. In the grasping portion of the treatment tools, the bifurcated distal ends are configured to have the same lengths in order to completely remove target tissues by high-frequency treatment (see JP-A-5-42167, for example).
In order to completely remove target tissues such as polyps, it is necessary to control the direction of the grasping portion so that the base of the tissue is disposed between the bifurcated distal ends. The treatment tool is used by being inserted into a channel provided along a scope of an endoscope. Operators such as a physician usually operate the scope, not the treatment tool. Therefore, when operators manually locate the grasping portion, the operators move one of the distal ends of the grasping portion to press against a tissue adjacent to the target tissue and rotate the scope itself about the one distal end.
However, there are many irregularities around the tissue such as polyps. In the case of the treatment tool disclosed in JP-A-5-42167, even a trial to move the one distal end of the grasping portion to press against the adjacent tissue may result in the other distal end making simultaneous contact with the adjacent tissue. In this case, it becomes difficult or impossible to rotate the grasping portion, thereby causing problems in locating the grasping portion.